What Are Ultra-Processed Foods? (And How to Spot Them)
By R.Davies, PhD・Nutrition
Published on January 02, 2026
Ultra-processed foods are industrially manufactured products made from ingredients that have been significantly altered from their original form.
You won't find them, in any form, growing in the wild. They are made by man, not by nature.
This article introduces what ultra-processed foods actually are.
Supermarkets are filled with foods ranging from those that have been minimally changed from when they were harvested in the field to highly processed products that are no longer recognisable.
These differences matter because emerging research suggests that how (and what) food is processed may affect your health. This occurs over and above the nutritional content of the food alone.
Ultra-processed food (UPF for short) has become a focus of health and nutrition science over the past decade.
But before we look further any further into them, it is useful to define what a UPF actually is and how you can identify them.
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What are ultra-processed foods?
In 2009, researchers at the University of São Paulo introduced a 'framework' to categorise foods based on the processing they’ve been through and what they’re used for [1].
This system divides foods into four groups.
Group 1: Unprocessed and Minimally Processed Foods
These are foods in their natural state or altered only slightly.
Examples include fresh vegetables and fruits, eggs, milk, plain yoghurt, dried beans, and frozen vegetables.
The processing these foods go through is minimal, usually just washing, removing inedible parts, drying, freezing, or pasteurising for safety.
Group 2: Processed Culinary Ingredients
This group includes 'extracts' from Group 1 foods that are used in cooking.
Think olive oil (from olives), butter (from milk), sugar (from plants), salt (from the sea), and honey (from honeycombs).
You wouldn't (or shouldn’t) eat these alone for a meals, but they are there to help prepare other foods (ideally from group 1).
Group 3: Processed Foods
These foods result from adding Group 2 ingredients to Group 1 foods.
The goal of this type of processing is (primarily) to preserve the food product or improve its flavour.
Canned vegetables with salt, tinned fish in oil or brine, freshly made bread (just flour, water, salt, yeast), and simple cheeses fall into category 3.
These foods aren’t inherently bad (in limited amounts), as they still retain a lot of their original nutritional value.
Group 4: Ultra-Processed Foods
This category includes products that are made mostly or entirely from substances derived from food (group 2) and artificial substances (like preservatives and other additives).
Little of the Group 1 food is still intact.
To make these foods, companies use industrial processes like hydrogenation, extrusion, moulding, and pre-processing for fractionation. Not processes you can easily do at home.
The result is products designed for convenience, palatability, and shelf life — not nutrition (or health).
Definition of 'ultra-processed'?
There’s no single quick rule that you can use to define UPF. But there are several things to look out for that they all have in common.
1. Industrial Formulations:
UPFs are typically created in factories rather than kitchens. They contain ingredients rarely used in home cooking, like protein isolates, modified starches, hydrogenated oils, and artificial additives.
These things are added for flavour, texture, or shelf-life, not for nutrition.
2. Multiple Processing Steps:
The creation of UPFs involves several industrial processing techniques. A group 3 food may go thorough one or three processes, whereas a UPFs go through dozens.
Studies show that these processes alter the food in ways that negatively affect digestion and metabolism for your health.
3. Ready to Consume:
Most UPFs require little or no preparation. They're designed for immediate consumption or simple heating (usually the microwave). This convenience means you're more likely to eat them, eat more of them, and eat them more often.
4. Palatability Engineering:
Manufacturers formulate UPFs to maximise taste by combining fat, sugar, salt, and other flavourings.
While these ingredients aren’t inherently toxic, they tend to be overconsumed (compared to minimally processed alternatives), which negatively affects your health.
5. Number of ingredients:
While not a perfect rule, UPFs typically have long ingredient lists containing things you wouldn't find in a home kitchen.
Look for unfamiliar ingredients like maltodextrin, modified corn starch, protein isolates, or various numbered additives.
Having a long ingredient list doesn’t define a UPF by itself, as some healthy food products might have many ingredients as well.
6. Packaging & Marketing:
UPFs typically come in manufactured packaging with health claims and appealing graphics. They're typically colourful and positioned as a convenient meal replacement or snack.
The package might emphasise fortification with vitamins or minerals, attempting to convey nutritional value.
Typical examples of UPFs include: soft drinks, packaged snacks, mass-produced bread, sugary breakfast cereals, instant snacks, energy bars, chicken nuggets, hot dogs, and microwave meals.
Notably, price doesn't determine the level of processing its been through. Both budget and premium products can be 'ultra-processed'.
Grey Areas
Not everything fits neatly into these four categories.
Some products fall outside and occupy a middle ground. For example, plant milks, protein powders, protein bars, flavoured yoghurts, and “whole-grain” products are all difficult to allocate to specific categories.
Some of UPF products can be made with natural ingredients, sweeteners, and minimal processing (or even at home).
However, other products in the same category contain artificial additives, preservatives, flavourings and have been through multiple rounds of processing.
Not all UPF products are created equal.
These grey areas highlight a limitation. So the classification system is a tool, not a rule. Don’t expect them to accurately capture and classify every product you buy at the supermarket.
Why do we need definitions anyway?
The short answer is the consumer probably doesn’t.
No one is going to go around the supermarket with a 26-point checklist, trying to see which group every item on your list is before putting it into your basket.
However, researchers require strict definitions so they can analyse them.
How many UPFs do people eat? How many UPFs do different groups of people eat? How do they affect health? What type of UPFs do people eat? Why do people eat UPFs? What would happen if we taxed UPFs or limited their availability? How can consumers identify or be aware of UPFs?
All these questions require strict criteria to define them. But as individual people, most of us don’t have to worry about rigid rules and technical definitions.
Eating the occasional UPFs isn’t going to negatively affect your health by itself; problems start to arise when UPFs dominate your diet, eaten every day and in place of healthy foods.
Context also matters. Someone with limited time, resources, or access to fresh food might rely more on UPF options. That's a practical reality, not a moral failing.
The goal of the classification of UPFs at this stage isn't about judgment but understanding what they are.
Looking Ahead
UPFs are now embedded in many food systems around the world. Defining them is just the first step. The next thing we need to know is how these products become so popular.
What factors drove their expansion from niche convenience items to dietary staples?
Next in this series: Why UPFs Became So Popular
Sources
1. Monteiro CA et al. Ultra-processed foods: what they are and how to identify them. Public Health Nutr. 2019 Apr;22(5):936-941. PMID: 30744710
Published: January 02, 2026
Lead Author: R.Davies, PhD | Author Bio
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